Interpolymers of castor-oil maleate



Patented May 1, 1951 TENT FFICE 2,551,352 INTERPOLYMERS OF CASTOR-OIL MALEATE Pliny 0. Tawney, Passaic, N. J., assignor to United States Rubber Company, New York, N. Y., a

UNITED corporation of New Jersey No Drawing. Application March 18, 1949, Serial No. 82,297

respects well adapted-to the preparation of coating and laminating compositions which, after application, can be cured to a solventand heatresistant state. In this connection they are particularly suitable for blending with other thermosetting resins, e. g., urea-formaldehyde resins and melamine-formaldehyde resins, to secure more flexible products. However, such resins derived from castor-oil maleates of high acid number, e. g., 50-100, i. e., those containing relatively both styrene and trichloroethylene, the customary premature gelation of the reaction mixture is averted or postponed to such an extent that markedly improved yields of soluble, convertible resins, which are new ternary interpolymers, are obtained. Moreover, asthe amount of the monomeric interpolymerizable trichloroethylene in the initial reaction mixture is increased, the yield of the resulting soluble ternary interpolymers is likewise increased, and in this way, it is now possible to convert the major proportion of both the castor-oil maleate and the styrene to the soluble interpolymeric form without danger of premature elation.

Although styrene has been cited above as illustrative of the monoolefinic compounds which are suitable for copolymerization with oastor-oil maleates in the method of my invention, various substituted styrenes may also be employed, including the alphaand para-substituted styrenes, e. g., p-chlorostyrenes, p-methylstyrene, alpha,pdimethylstyrene, p-fiuorostyrene, p-trichlo'romethylstyrene, p-methoxystyrene, and 2,5-dilarge amounts of maleic acid ester groups (su h chlorostyrene. The styrenes can be replaced in as are obtained, for example, from the reaction of Whole p by er monoolefinic hydrocar- 1 mole of caster-oil with 2-3 moles of maleic bonfi, Vinyl naphthalene and aliphatic anhydride in a manner well known to those skilled finic hydrocarbons especially the lower aliphatic in the art), tend to form an insoluble gel during Olefinic hydrocarbons, i. those having 2 6 the copolymerization reaction and before more Carbon atoms ethylene, propylene and than a minor proportion of monomers has been .m but-719116, although many of the more reactive converted t t opolymeric f rm Such prodolefins sufier the economic disadvantage of being ucts are of limited commercial utility since the gases at room temperature and hence they will presence of the masses of insoluble gel eifects 1eql ire'13res5uTiZed equipment for the copoly' serious discontinuities in the resulting coating or merlzation reaction laminate such as cracks, lumps and blisters. A other Suitable D Y abIB oolefi c soluble resin can be obtained, albeit in low yields, Compounds which may be used in place of ene by halting the copolymerization priOr to gelation, but Which tend to yield softer resins, include vinyl although the large amounts of unreacted mon0 mono-esters of non-enic acids, e. g., vinyl acetate, meric starting materials remaining must be. re- Vinyl butyrate and Vinyl benzoa-tey and mono moved, purified and recycled for use in subse- Vinyl ethers Vinyl ethyl ether, Vinyl I DY quent copolymerization in order to achieve some ether d Vinyl ben y t er, d t e es s-0f degree of economic feasibility The Comlmherimonoolefinic monocarboxylic acids with nonzation of castor-oil, maleates of relatively low Bnic alcohols, methyl c y a e, 431117511 acryacid number, e. g., 20-40 (su h a a b blate, tolyl acrylate, methyl methacrylate, ethyl tained from the reaction of 0.3-0.6 mole of maleic chloroacrylate and methyl crotonate- The o anhydride' with 1 mole of castor-oi1),with styrene l fini cids h m e v c n be empl yed 1- shows a, dimini he tendency to r premature though the resulting resins are more sensitive to gelation but the resulting resins are softer, less Water and other yd y So ven a d t0 alkalimar-resistant and often require more stringent Besides esters, other hydl e de es of curing conditions to achieve a satisfactory degree Such monoolefinic acids can be employ d, Suc of solventand heat-resistance in the final prodas t d de's, a d chlo ides, nitriles and not than those derived from the castor-oil maleamides, the two latter yielding resins which are ates of higher acid number. harder but compatible with fewer solvents.

I have now unexpectedly discovered that when The caster-oil maleates, as is well known to a castor-oil maleate is interpolymerized with 56 those skilled in the art, are prepared by the es- 3 teriflcation of m'aleic acid or maleic anhydride with castor-oil. Usually about 1 mole of castoroil is employed per mole of maleic anhydride. This invention also contemplates the employment of castor-oil esters obtained by substitution of some or all of the maleic anhydride by the homologues of maleic acid, such as citraconic acid or citraconic anhydride. If desired, various modifying ingredients, such as linseed oil, may be washed with methanol before drying in vacuo to constant weight.

Table I below summarizes the amounts of the castor-oil maleate, monoolefinic compound, trichloroethylene, and benzoyl peroxide, and the resulting soluble interpolymer, as well as the reaction times. To further illustrate the advantages of my invention, examples of the prior art copolymerization in the absence of trichloroethylpresent in the reaction mixture during the prep- 10 ene are also included (I-a, b, g, i).

Table I claistlor-oil c. eate Monoolelinic Com- Triehloro- Benzoyl gfigg f ff f pound Ethylene Peroxide H C I IS. mCl' Parts No a. 100 54 Styrene, 121 1. 1 4. 7 G0 15. 2 (1...- 100 54 do 180.0 2.04 6.4 60 24.2 c 100 54 5 1. 46 4. 7' 00 24. 4 (L--- 100 54 .0 1.87 8.8 60 38.4 e 100 54 2.61 12. 2 ($0 55.0 f 100 54 8. 75 71. 0 00 130. 0 u 100 71 1.07 0.8 80 8.5 IL.-- 100 71 0 485.0 3.52 3.3 80 09.5 in.-- 100 54 Vinyl Acetate, 100 l. 0 9. 0 00 21. 7 j- 100 54 do 368 15.15 71.0 00 i 80.5

1 Trichloroethylene replaced by an inert solvent, benzene.

aration of the ester to be employed in this invention.

In the practice of my invention a castor-oil maleate, preferably one having an acid number of from about 30 to 100,.is reacted with a copolymerizable monoolefinic compound, and with trichloroethylene, in molar ratio of 1:0.5z120 to :4:120, respectively, and more preferably 1:3:50 to 12:6:50. The reaction is ordinarily carried out at temperatures in the range of to 120 C., particularly in the range 40-100 C. for a time sufficient to form at least an appreciable quantity of the soluble interpolymer. Suitable reaction times will usually be found to be from 4 to 80 hours. Suitable promoters or catalysts for the reaction include conventional sources of free radicals such as organic peroxides, e. g., benzoyl peroxide, acetyl peroxide and tertiary-butyl hydroperoxide, in amounts of from about 0.1 to 10.0% by weight of the total interpolymerizable reactants.

During the reaction, the increasing viscosity of the reaction mixture can be employed as a measure of the extent of the reaction. The resulting soluble interpolymer can be isolated from the reaction mixture by evaporation of any unreacted trichloroethylene or by precipitation of the interpolymer through addition of a non-sol- EXAMPLE 1 Castor-oil maleate is interpolymerized with styrene or vinyl acetate, respectively, together with trichloroethylene, in the presence of benzoyl peroxide until the point of incipient gelation is attained in each case. The reaction mixtures are then diluted with an excess of methanol and the precipitated interpolymers are thoroughly Comparison of I-a with I-c above shows that the presence of even relatively small amounts of the interpolymerizable trichloroethylene in the interpolymerization of castor-oil maleates with monoolefinic compounds effects a very significant increase in the yield of soluble interpolymeric product. Succeeding examples indicate further increases in the yield of soluble interpolymer which are obtained when larger amounts of the trichloroethylene or employed.

EMMPLE 2 A mixture of 54 parts of castor-oil maleate (acid number, 71), 52 parts of styrene and 263 parts of trichloroethylene is heated at C. for 2 hours in the presence of 1.16 parts of benzoyl peroxide, to yield 47 .9 parts of soluble interpolymer which can be converted to a solventand heat-resistant state by heating at elevated temperatures, e. g., -200 C.

Five and six hundredths parts of a 34.6% solution of the above soluble interpolymer in xylene is admixed with 1.37 parts of a 54.8% solution of a commercial urea-formaldehyde solution in xylene. The mixture is thinned to a pourable viscosity by the addition of xylene and is then poured onto a glass plate. After heating at C. for 30 minutes a clear, tough insoluble film is obtained.

EXAMPLE 3 A mixture of 27 parts of castor-oil maleate (acid number, '71), 31 parts of styrene, 213 parts of trichloroethylene and 1.3 parts of benzoyl peroxide is heated at 80 C. for 6.1 hours with stirring, and in an atmosphere of carbon dioxide.

The reaction mixture is thn evacuated at 40 C. and the residual resin is diluted with about 100% by weight of xylene. This solution is mixed with a 50% solution of urea-formaldehyde resin in xylene in such a way that a 70:30 blend (by weight) of my interpolymer and the urea resin in obtained. The solution is then thinned to a desirable viscosity by a 1:1 xylene-butanol mixture and poured onto a panel. After baking for 30 minutes at 150 C. a hard, tough, colorless, insoluble film is obtained.

Having thus described my invention, what I claim and desire to protect by Letters Patent is:

1. A method which comprises heating a mixture of (a) 120 moles of trichloroethylene, (b) 1 to 20 moles of an ester of castor-oil with an unsaturated dibasic organic acid selected from the group consisting of maleic acid and its homologues and (c) 0.5 to 4 moles of another copolymerizable monoolefinic compound at a temperature sufficient to effect copolymerization of the said ingredients, in the presence of an organic peroxidic polymerization catalyst in amount effective to cause copolymerization of said ingredients, whereby a fusible, convertible interpolymer of the said ingredients is formed.

2. A method which comprises heating a mixture of 120 moles of trichloroethylene, 1 to 20 moles of an ester of caster-oil with an unsaturated dibasic organic acid selected from the group consisting of maleic acid and its homologues, and 0.5 to 4 moles of another copolymerizable monoolefinic compound at a temperature of 25 to 120 C. in the presence of an organic peroxidic polymerization catalyst in amount of from 0.1 to 10.0% by weight of the aforesaid reactants, whereby a soluble, convertible interpolymer of the said reactants is formed.

3. A method which comprises heating a mixture of 50 moles of trichloroethylene, 1 to 12 moles of a caster-oil maleate having an acid number of 30 to 100, and 3 to 6 moles of another copolymerizable monomer at a temperature of 40 to 100 C. in the presence of an organic peroxidic polymerization catalyst in amount of from 0.1 to 10.0% by weight of the aforesaid reactants, whereby a soluble, convertible interpolymer of said reactants is formed.

4. A method as in claim 3 in which the additional copolymerizable monoolefinic compound is styrene.

5. A method as in claim 3 in which the additional copolymerizable monoolefinic compound is vinyl acetate.

6. A method as in claim 3 in which the additional copolymerizable monooiefinic compound is a lower aliphatic monoolefinic hydrocarbon having from 2 to 6 carbon atoms.

7. An interpolymer of trichloroethylene, an ester of castor-oil and an unsaturated dibasic organic acid selected from the group consisting of maleic acid and its homologues, and another copolymerizable monoolefinic compound.

8. An interpolymer of trichloroethylene, a castor-oil maleate, and another copolymerizable monoolefinic compound.

9. An interpolymer as in claim 8, in which the copolymerizable monoolefinic compound is styrene.

10. An interpolymer as in claim 8, in which the copolymerizable monoolefinic compound is vinyl acetate.

11. An interpolymer as in claim 8, in which the copolymerizable monoolefinic compound is a lower aliphatic monoolefinic hydrocarbon having from 2 to 6 carbon atoms.

PLINY O. TAWNEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,976,224 Herrmann et a1 Oct. 9, 1934 2,439,953 Swiss et al. Apr. 20, 1948 

1. A METHOD WHICH COMPRISES HEATING A MIXTURE OF (A) 120 MOLS OF TRICHLOROETHYLENE, (B) 1 TO 20 MOLES OF AN ESTER OF CASTOR-OIL WITH AN UNSATURATED DIBASIC ORGANIC ACID SELECTED FROM THE GROUP CONSISTING OF MALEIC ACID AND ITS HOMOLOGUES AND (C) 0.5 TO 4 MOLES OF ANOTHER COPOLYMERIZABLE MONOOLEFINIC COMPOUND AT A TEMPERATURE SUFFICIENT TO EFFECT COPOLYMERIZATION OF THE SAID INGREDIENTS, IN THE PRESENCE OF AN ORGANIC PEROXIDIC POLYMERIZATION CATALYST IN AMOUNT EFFECTIVE TO CAUSE COPOLYMERIZATION OF SAID INGREDIENTS, WHEREBY A FUSIBLE, CONVERTIBLE INTERPOLYMER OF THE SAID INGREDIENTS IS FORMED. 